The present application generally relates to a downhole initiator, and more particularly, to an initiator for an oil or gas well environment, which contains a safety barrier to prevent inadvertent firing of the initiator.
Explosives typically are used in an oil or gas well for such purposes as perforating a well casing and forming perforation tunnels in a surrounding formation to enhance the productivity of the well. More specifically, a well tool called a perforating gun typically is run downhole in the well on a conveyance mechanism, such as a wireline, slickline, coiled tubing string, jointed tubing string, etc. When the perforating gun is in an appropriate position adjacent to the formation to be perforated, perforating charges (shaped charges, for example) of the perforating gun are fired to create perforating jets, which penetrate the casing and form the perforation tunnels in the formation.
A typical wireline-based perforating gun may include an initiator that is constructed to fire perforating charges of the gun after the initiator detects the appropriate command that is communicated downhole to the perforating gun from the surface of the well. The initiator may include an igniter, such as a semiconductor bridge (SCB), hot wire, exploding bridgewire (EBW) or TiB igniter, which is energized by the initiator after the initiator detects the command. When energized, the igniter sets off an explosive to begin a chain of explosive events that ultimately results in the initiation of a detonation wave on a detonating cord. The detonation wave causes the perforating charges (which are connected to the detonating cord) to fire.
Care typically is exercised for purposes of preventing inadvertent firing of the perforating charges. However, challenges remain in preventing an unintended triggering event, such as an electrostatic discharge (ESD) or a radio frequency (RF) signal, from causing inadvertent firing of the perforating charges.